John hall



(No Model.)

J. HALL.

j J Air Brake for Railroad Trains. No. 231,311. Patented Aug. 17,1880.

WITNESSES; INVENTOR:

%M Mqm c/V Na ATTORNEYS.

I PETERS. PHOYO-LITMQGRAFHER. WASHINGTON D C UNITED STATES PATENT (OFFICE.

JOHN HALL, OF HAMILTON, ONTARIO, CANADA.

AIR-BRAKE FOR RAILROAD-TRAINS.

SPECIFICATION forming part of Letters Patent No. 231,311, dated August 1'7, 1880.

Application filed J une 4, 1880. (No model.)

To all whom it may concern Be it known that I, JOHN HALL, of Hamilton, in the Province of Ontario and Dominion of Canada, have invented a new and useful Improvement in Air Brakes for Railroad- Trains, of which the following is a specification.

The object of my invention is to utilize the momentum of railroad-trains for stopping or checking the trains by using the pistons and cylinders of the locomotive as pumps for compression of air, either as a resisting force upon the piston-head alone or for use with airbrakes of ordinary construction.

In reversing the valves of a locomotive, as usual, to check the speed, the piston'heads draw air during more or less of their stroke, and on the return stroke such air is forced into the steam-chest, and in a short time is forced into the boiler. The difficulties from this action are,first, the great increase of pressure in the boiler, generated so rapidly that the safety-valve is not sufficient to free it, so that it often amounts to twice the normal pressure; second, the air being drawn from the smokebox is mingled with gases, ashes, and other impurities, so that injury is done to the cylinders and valves; and, third, the difficulty of changing the dry and heavily-weighted valves after reversal and the risk of breaking the couplings, as there are no means for releasing the weight below the throttle-valve when the engine is running reversed.

My invention consists in certain devices, which are combined with the exhaust-pipes and throttle-valve of the locomotive, for preventing the difficulties above named and permitting the convenient and effective application of the momentum inchecking the train.

The construction and operation will be explained in detail with reference to the accom panying drawings, wherein Figure 1 is a sectional side elevation, showing the forward end of a locomotive-boiler and the parts contained in the smoke-box. Fig. 2 is a front view, the casing of the smoke-box being removed. Fig. 3 is a vertical section of the exhaust-nozzles.

Similar letters of reference indicate correspondin g parts.

A is the boiler-shell.

a is the steam-pipe,

formed with branches passing through the smoke-box in the usual manner to the cylinders, which are not shown. I) I) are the exhaust-pipes from the cylinders, terminating in the nozzles c, of usual construction. The shell of the smoke-box is shown by dotted lines.

To the nozzle 0 is connected a pipe, d, that extends horizontally forward and through the front of the smoke-box, terminating with a flaring month. In, this pipe is a cock, 0, the stem of which extends through the side of the smoke-box, and is provided with a crank, upon which a rod, 6, is connected, and said rod will pass to the cab for operation by the driver. There is also upon the stem of cock 0 an arm, f, that connects, by ajointed rod,with a slide, g, that rests on the nozzles 0, so that the slide 9 is moved to cover or uncover the nozzles simultaneously with the opening and closing of cock e.

The nozzles c are formed with a side extension, 0, upon which the slide g moves in .uncovering the nozzles.

From the steam-pipe a rises a pipe, h, which extends through the top of the smoke-box, and is formed at its upper end with a seat for a valve, t. On pipe his hung'alever, 7a, which bears on valve t, and carries at its outer end a spring, I, for holding the valve down with a regulated pressure. This valve serves as a relief or safety valve, and .for convenience of access is placed behind the smoke-stack.

In suitable bearings upon boilerAis fitted a rock-shaft, m, carrying an arm ,m, to which the spring I of valve i is connected. On shaft m is fixed an arm, a, carrying a pawl, a, that engages with a notched segment, 0, for the pur* pose of holding the shaft m in position as turned by arm 'n, to give the spring I more or less tension.

From the pipe h, below valve 2', a pipe, 8, extends, which pipe will be connected to the tubes of usual air-brake mechanism or to the air-drum of such mechanism.

In the pipe 8 is a T, fitted with a three-way cock, p, which maybe turned to connect pipes h and s, or to connect pipe h with the branch 0 of the T. This branch 0 will be connected to a suitable reservoir on the locomotive, so that the compressed air may be stored in the said reservoir, and from thence discharged to pipe 8, or the reservoir may be cut out and the steam chests and pipes utilized as a reservoir.

To permit operation of the cock 1), I use a tube for the rock-shaft m, before mentioned, and extend the stem 1 of cock 1) through said shaft, and on the end of stem 1 is a handle, 1*, for its operation.

This furnishes a simple and compact construction, and it will be understood that the operating handles and lovers will all be placed in position for convenient operation by the driver.

This mechanism is to be used for stopping a train or for simply checking the momentum on an incline.

In operation, when it is desired to hold a train on an incline, with the steam-pressure in the boiler-say one hundred poundsthe throttle-valve will be closed, the shaft at will he turned to give a minimum pressure of twenty pounds on valve 4', and the cock 0 will be opened to connect the nozzles v with the outer atmosphere through pipe d, the nozzles being at the same time closed by the slide g. The valves are then to be reversed, and the air pumping and delivering goes on against a resisting pressure of twenty pounds. If this pressure is not sufticient to hold the train, additional pressure is to be given to valve 1' as required. The momentum may thus be used to create a resisting force from a minimum pressare oftwenty pounds up to the amount of steampressure. This force may be utilized, as mentioned, as an auxiliary to the air-l)1akesb \,'passing the air into the cylinders on the cars, intead of, as now done, by special reservoirs and independent pumping-machinery; or, where air-brakes are not used the resisting force upon the piston-heads may be depended upon for holding the train.

The invention is specially useful for freight engines and trains, and permits the engineer to control the train without depending on the brakemen.

Having thus described myinvention, I claim as new and desire to secure by Letters Patent- 1. The combination, in an air-brake, with the locomotive exhaustpipes, the nozzles 0, having extension 0, and the tube d, of the cook a, having stem whose crank connects with the cabrod 0', and a slide, g, connected by a jointed rod with an arm, f, of the cock-stem, as and for the purpose described.

2. The combination, with the steam-pipes a, of a relief-valve, 1', arranged in a vertical pipe, b, passing through the smoke-box, and having a valve-seat at its upper end to release com pressed air, as specified.

3. The shaft 122, having arm m, spring 1, arm n, carrying pawl n, and notched segment 0, combined together and with the lever k of the relief-valve, substantially as and for the purposes set forth.

4. In combination with the steam-pipe of a locomotive fitted with a relief-valve, the pipe 8, connected below the relief-valve and adapted for connection to the pipes of the air-brake, and the cock 2 in the pipe s, substantially as and for the purposes set forth.

JOHN HALL. Witnesses:

F. ARMSTRONG, W. S. BRIGGS. 

